Anderson U.S. Pat. No. 4,195,978 discloses a coal slagging gasifier and method of operating improved by providing a slag removable orifice.
Bowden et al, Synthetic Fuels from Coal, Alternative Energy Sources Symposium, Feb. 9-13, 1980, discusses a Lurgi dry-bottom gasifier which in FIG. 1 is shown to produce crude synthesis gas. This gas enters a quench vessel in which the tars are condensed and particulate matter occludes to the tar. The water dissolves some of the phenols and ammonia, while gas exits the quenched scrubber at about 475.degree. K. or less and passes through a waste heat boiler. At page 160 second paragraph from the bottom at item 5 under other disadvantages of the Lurgi gasifier. Bowden states that the synthesis gas from the Lurgi gasifier contains 8 to 15 percent by volume methane which must be removed or reformed before the gas can be used for chemicals manufacture. Also on page 160 Bowden et al mention that synthesis gas from Lurgi gasifiers can also be used to manufacture such chemicals as methanol.
Hempill et al U.S. Pat. No. 4,199,327 discloses coal gasification in a slagging gasifier with CO.sub.2 and H.sub.2 S removal wherein the final gas product is used for methanol production, power plant, methanation plant or chemical feedstock preparation purposes.